First SLAM not sure if things are working right.

Levy2725

Member
Jun 17, 2019
8
Bristol, Vermont
We bought a house in November with a pool and are going through the process of opening it for the first time. The previous owner has been helpful in getting all the mechanical and plumping elements working right but has pretty much just directed us to this forum for chemistry questions. The materials here have been super helpful but I'm still pretty uncertain if I'm on the right track.

The pool was pretty green and murky when we took the cover off. We added water and then ran the pump and the vacuum for about 24 hours to try and clear out some of the big muck. I began my first SLAM Monday around noon. Initial readings were a pH of 7.4, a TA of 40 and no chlorine or CYA. Per the pool math calculator, I started with 59 oz. of dry stabilizer, hung in a cheesecloth in front of the filter intake, and 180 oz. of liquid chlorine at 12.5%. After testing, I've only had to do two other chlorine additions to stay above shock level -- a similar size add about 4-5 hours later and a much smaller add on Tuesday morning. Chlorine was well above shock level all day yesterday.

I tried the first overnight loss test from Tuesday into Wednesday and got readings of 15 FC and .8 CC at 9:30 PM and 13 FC and .6 CC this morning. Seems like I'm not losing much chlorine to organic material but pool math says to add more this morning to stay above shock level. The pool has cleared up significantly and the green is completely gone but the blue water is still very cloudy. We've been running the pump (at about 2000 rpm) and the vacuum continuously but the cloudiness doesn't seem to be improving. Stick with the SLAM procedure and the pump/vacuum combo should take care of the cloudiness? Or is it possible there's something else going on that's making the water cloudy?
 
You seem to be on the right track. Staying with the SLAM will make sure you kill all the algae. You need POP (Pool Owner Patience) as cloudy will take a while to clear. Last year I had an algae bloom and while I went from green to blue in a day, it took 3 weeks to get to clear and the TFP sparkle.
 
Welcome! :wave:

It sounds like you have done your homework and are on the right track. What test kit are you using? Can you post some pictures of your pool so we can see how things look? This will also help you see how things progress each day.

Keep up with the SLAM and let the filter do its thing. Keep an eye on the filter pressure. When it raises 25% from its clean PSI, be sure to backwash it. It will take some time for the water to clear up completely, but don't let up on the SLAM process or the algae may return.
 
Welcome to TFP!

Two things I noticed: First you are aiming for your SLAM level, not attempting to stay above it. It won't speed things up overshooting but it will cause you to burn off chlorine faster during the day. Second is that you can use a 10 ml sample for your FC/CC test. Use 10 ml of water, 1 scoop of powder, and then each drop counts as 0.5 ppm instead of 0.2. Will save you a lot of reagents.

Other than that, just keep with it. You are in the stage where the major color has shifted but has to clear out. Keep vacuuming and/or brushing to make sure chlorine is hitting everywhere and everything. You got this, and other than the two things I mentioned you seem to be handling it perfectly. The most common thought at this point is thinking that something uncommon is going on ? It's normal, and it's getting better every day even if you don't notice it.
 
Thanks, everyone. I really appreciate the positive support. Good to know I'm on the right track.

I've been watching the filter pressure and I'll make sure to backwash. So far it hasn't moved much.

I'm using a Leslie's FAS-DAP test kit. I'll try to sneak out and grab some pictures later today.

Thanks!
 
Hi all, a few quick follow-up questions! Water is clear, passed an overnight loss test without losing any FC and I didn't read any CC on my test this morning. FC is still at 6.5, is it safe to swim at that level or should I wait until it drops down to 4 or so?

Also, my CYA was 0 when we opened the pool so at the beginning of the SLAM I brought it up to 40. Over the past two weeks it has dropped down below 20. Should I be bringing it back up to 40? Should I expect to try and maintain it at that level with cyanuric acid additions every few weeks? From what I've read here in the forum I got the impression that CYA levels shouldn't change that quickly or require such frequent management.

Thanks!
 
Your FC is below your SLAM value of 10, so swimming is fine since you say the water is clear. It's likely you lost CYA backwashing and replacing water. I'd shoot for 30 or so now, and if it continues to drop (splashout, backwashing) maybe aim for 40ish.
 
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